PROJECT SUMMARY/ABSTRACT HIV/AIDS and heavy alcohol use are highly comorbid, and the combination greatly increases the likelihood of adverse health outcomes. The neurotoxic effects of comorbid HIV and heavy alcohol use preferentially impact the corpus callosum and frontal white matter, leading to increased prevalence of neurocognitive disorders characterized by deficits in motor skills, verbal working memory, visuospatial skills, and executive functioning. Although often mild in severity, these neurocognitive impairments subsequently lead to greater risk for dependence in activities of daily living, poor HIV disease management, and accelerated HIV disease progression. Despite the significant consequences of neurocognitive impairment in this population, there is a general lack of reliable and valid tools to identify those who may be at risk for these impairments. Self-report assessments of cognitive functioning are often used to briefly assess for neurocognitive impairment in many clinical populations; however, the retrospective nature of all current measures of self-reported cognitive functioning reduces accuracy due to recall errors, social desirability effects, cognitive deficits, or state dependent bias. For example, the internationally recommended European AIDS Clinical Society (EACS) neurocognitive screening questions are retrospective and may be improved by repeated administration via ecological momentary assessment (EMA). EMA is an innovative mobile assessment method that increases ecological validity and reduces retrospective recall errors by collecting real-time, real-world data. EMA thus represents a potentially powerful technique to improve measurement of self-reported cognitive functioning and detect risk for neurocognitive impairment in high-risk clinical populations such as people with HIV who drink heavily. Accordingly, the proposed F31 dissertation project aims to: 1) evaluate psychometric properties of the EMA-administered EACS screening questions; 2) examine temporal relationships among EMA self-reported alcohol use, mood, and cognitive complaints; and 3) examine potential effects of demographics, HIV disease characteristics, and cognitive complexity of daily activities on self-reported cognitive complaints. Given the current absence of such assessment techniques in this population, results from this study will inform future development of novel mobile assessment methods to detect neurocognitive impairment in HIV and heavy alcohol use. The opportunities afforded via this F31 mechanism will significantly contribute to the applicant?s long-term goal of becoming an independent academic neuropsychologist dedicated to early detection of neurocognitive impairment among individuals with comorbid HIV infection and heavy alcohol use.